Slider adjustments

[flip111]

The slider doesn't really work so well fine grained. With SHIFT it still makes +5 steps. It would be more useful to make +1 steps.

It would also be nice to use scrollwheel to do -1 and +1

[sharkdp]

There are hotkeys for a lot of different settings. Unfortunately, they are not documented (#12), but you can see them here: https://github.com/sharkdp/binocle/blob/master/src/event_loop.rs#L109-L217